// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

#ifndef STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_
#define STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_

#include "leveldb/iterator.h"

namespace leveldb
{

    struct ReadOptions;

    // Return a new two level iterator.  A two-level iterator contains an
    // index iterator whose values point to a sequence of blocks where
    // each block is itself a sequence of key,value pairs.  The returned
    // two-level iterator yields the concatenation of all key/value pairs
    // in the sequence of blocks.  Takes ownership of "index_iter" and
    // will delete it when no longer needed.
    //
    // Uses a supplied function to convert an index_iter value into
    // an iterator over the contents of the corresponding block.
    Iterator *NewTwoLevelIterator(
        Iterator *index_iter,
        Iterator *(*block_function)(void *arg, const ReadOptions &options,
                                    const Slice &index_value),
        void *arg, const ReadOptions &options);

} // namespace leveldb

#endif // STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_
